FROM AROUND THE STATE
ISSUE 11 July 13, 2000
Orange wheat blossom midge emergence is peaking for the north
Fields should be scouted in the heading to early flowering stage to
populations below threshold.
1 wheat midge per 4-5 wheat heads
When to scout? At night, after 9:00 PM; light wind <6mph; temperature above 60oFFlight Reports: Wheat midge flight has been HEAVY (1 midge per 4-8 heads) in the Divide
For the Degree Day (DD) Model, 50% emergence of the females is by 1450 DD
emergence by 1600 DD, using a 40"F Base. The following insect DD have been accumulated as
of July 11, 2000: Rollette Co., Rolla = 1423, Burke Co., Columbus = 1436, Bottineau Co.,
Bottineau = 1518, McHenry Co., Towner = 1601; Renville Co., Mohall = 1538, McLean Co.,
Turtle Lake = 1667, Ward Co., Minot = 1666, and Williams Co., Williston = 1768 (Source: NDAWN).
Note: The 1999 WHEAT MIDGE TRIALS mentioned above are available of the
the North Central Research Extension Center, Minot website. Click on Pest Summaries.
Janet J. Knodel
Area Extension Specialist Crop Protection
North Central Research and Extension Center
Total rainfall as recorded at NDAWN sites in south-central ND during
July 5 to 11 ranged
from 1.04 inches at Dazey to 2.55 inches at McLeod. The rain was needed in Emmons and portions
of neighboring counties, but the balance of this region did NOT need more moisture. On July 11,
estimated daily water use of wheat emerged May 1, corn emerged May 15, soybean emerged
May 29, and sunflower emerged June 5 ranged from 0.04 inches in the north to 0.19 inches in the south.
Cool-season crop condition has deteriorated due to generally
excessive soil moisture, lodging, and
disease. The majority of the regions small grain crop is in various seed-fill stages. Winter cereal and
barley harvest will begin late this month. Flowering is nearly complete with fall- and early spring-seeded
canola and some swathing may occur the last week of July. Warm-season crops are rapidly developing.
Leaf spot disease (tan spot, leaf rust, and Septoria in wheat; spot
and net blotch in barley) severity is
rapidly increasing. The NDSU foliar disease forecasting model for the Carrington site indicated potential
for tan spot and leaf rust every day during July 2 to 11. Conditions for scab in small grain and sclerotinia
in canola continue to be very favorable and both diseases are beginning to being found. Aster yellows is
being found in canola. Ascochyta blight has appeared in chickpea in McIntosh County.
Accumulated degree days (DD) for orange wheat blossom midge as of
July 11 ranged from 1605
units at Harvey to 1956 units at Oakes. Midge emergence has peaked throughout the region and
populations continue to appear below economic levels. However, continue scouting wheat fields that
are at risk until 1800 DD have been reached. Black light trap counts for European corn borer at
Carrington have recently increased and monitoring for this insect should begin. Scattered canola
plants can be found with damaging populations of aphids.
Area Extension Specialist/Cropping Systems
Carrington Research and Extension Center